Anthropic heads toward IPO with about $18 billion of debt tied to it, $9 billion of it held by Blackstone at junk-level rates

Anthropic is about to go public as one of the most valuable companies in the world — and its debt is about to get rated junk.

The firm that told investors it owns $9 billion of that debt set the interest rate at junk levels from day one.

The Rate Tells the Story

Sounds backwards until you see the rate. Blackstone's funds bought in at a yield above 10% — what lenders charge a borrower they think is risky. Blackstone has been getting paid that premium since it wrote the check.

How the Deal Works

The structure is clever. Anthropic needs $63 billion worth of Google's AI chips. Instead of borrowing all that itself, a separate company buys the chips and rents them to Anthropic, with the rent paying the lenders back.

• Broadcom, which holds a strong A rating, guarantees more than $42 billion of the deal.
• Only about $18 billion depends on Anthropic alone — and Blackstone took half of that.

What Anthropic's Name Costs

An earlier $35 billion chip deal led by Apollo shows the premium attached to Anthropic's own credit:

• 5.75% on the portion Broadcom guaranteed
• About 8.5% on the portion riding on Anthropic

Now do the math on Blackstone's slice: $9 billion at 10% instead of 5.75% comes to roughly $380 million a year in extra interest. Anthropic brought in $16.8 billion last quarter — about $183 million a day.

So the junk rating on that slice costs Anthropic roughly two days of revenue a year.

Why Junk at All?

Credit agencies primarily want to know whether cash flow can cover debt. When KBRA gave Anthropic a BB+ in June — the highest junk rating — it had to work off a risk score because Anthropic never handed over its free cash flow or EBITDA. The analysts had to guess, and nobody hands out investment grade on a guess — least of all to a company planning $800 billion of compute spending through 2045.

Precedent: Tesla and Netflix

Tesla sat on that exact rung not long ago. In October 2021, it became the first company worth $1 trillion with junk-rated debt. A year later, S&P bumped it from BB+ to investment grade.

Netflix is the longer version of the same playbook. It started selling junk bonds in 2009 and kept at it for more than a decade, borrowing to pay for the shows that built its subscriber base. S&P had it at B+ — four notches deep in junk — as late as 2018. S&P rates it A now.

The Structure to Watch

Most of this financing leans on Broadcom's balance sheet, and Broadcom's own filing says the business depends on Anthropic's continued commercial success. Anthropic's revenue jumped from $11.5 billion to $16.8 billion in a single quarter.

As long as that growth continues, BB is probably a pit stop on the way to investment grade. The scary version is growth stalling while $18 billion of debt sits on a company its own lenders already priced as junk.

The rating agencies are essentially catching up to an interest rate Blackstone set on day one.